Automatic idler and take-up



Aug. 1, 1939.

AUTOMATIC IDLER AND TAKE-UP Filed Nov. 7, 1938 2 Sheets-Sheet 2 JAM 5s A. W555 J. A.I.WEIBB I 2,167,963

Patented Aug. 1, 1939 UNITED STATES PATENT OFFICE AUTOMATIC IDLER AND TAKE-UP James A. Webb, Corpus Christi, Tex. I I Application November 7, 1938, Serial No. 239.381 1 4 Claims. (01. 74-44211) This invention relates to an automatic idler and take-up designed for use in maintaining a substantially uniform tension on a belt, cab-1e or similar driving element.

An object of the invention is to provide an automatic idler or take-up which will increase the tension of the belt should it acquire too much slack and which will also relieve the tension of the belt should it acquire too much tension on account of atmospheric or other surrounding conditions.

It is another object of the invention to provide a device of the character described which is of very simple construction and positive and accurate in operation.

With the above and other objects in view the invention has particular relation to certain novel features of construction, operation and arrangement of parts, examples of which are given in this specification and illustrated in the accompanying drawings, wherein Figure 1 shows a sectional view illustrating the invention.

Figure 2 shows a sectional view taken on the line 2-2 of Figure 1.

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Figure 3 shows a sectional view of another embodiment taken on the line 22 of Figure 1, and

Figure 4 shows a fragmentary view of the track and the support to which the track is attached.

Referring now more particularly to the drawings wherein like numerals of reference designate the same parts in each of the figures, the numeral I designates a track having the end legs 2, 2 which are outwardly turned to receive the securing bolts 3, 3 which pass through suitable oblong slots 3 in the overturned portions of said legs, as shown in Figure 4 and which also pass through the supporting structure 5. The bolts are secured in place by the nuts 6 and the lock nuts I. The leg I, accordingly, may be adjusted as required and this adjustment may be facilitated by means of the adjusting bolts 8 which are threaded through the overturned portions of the legs 2 and whose inner ends rest against the bolts 3 as shown in Figure 4.

There is a main casing composed of similar side plates 9, 9a which embrace the track I. These plates may be secured together by the corner bolts It) or in any other preferred manner. On opposite sides of the track the casing is provided with the rollers II, II which bear against opposite sides of the track and form antifriction means to facilitate movement of the casing along the track. Between the plates 9, 9a the main pulley I2 is mounted to rotate. The side plates have the aligned slots I3, I3 therethrough in which the bearing plugs I I, I are mounted to slide. Cast integrally with the block I4 there is a spindle IE on which the pulley I2 is mounted to rotate. This block has a lug I'I thereon to which a spring gauge or other measuring device may be attached to determine the amount of adjustment of the pulley I2, as hereinafter explained.

The free end ofv the spindle I6 is tapered and fitted through a tapered, central bore in the bearing block I5, and may be secured thereon in any-preferred manner as by means of a clamp nut I3 screwed on to the outer end of the spindle. The bearing blocks I4, I5 are thus assembled together as a rigid unit. The block I4 has the inwardly turned lug I9 clamped to which is a leaf spring 20. Opposing the leaf spring there is a similar leaf spring 2 I, the ends of said springs being connected together as more clearly shown in Figure 1. The leaves of the spring H are secured in assembled relation by asuitable clamp 22 which is supported by the adjusting rod 23 which in turn is adjustably. connected to the anchor 24 which in turn is secured to one of the side plates as 9a.

In lieu of the leaf spring arrangement 2! a coil spring 25 may be employed, for lighter equipment, one end of said coil spring being attached to the anchor 24 and the other end of which is attached to the lug I 9. The tension on the spring 25 may be adjusted by a suitable adjusting nut 26 in an obvious manner.

Rotatably mounted in a suitable bearing in the side plate So there isa shaft 21 fixed on the inner end of which there is a friction wheel 28 and fixed on the outer end of which there isa beveled pinion 29. This pinion 29'is in mesh with, and drives, a similar beveled pinion 30 which is fixed on one end of the shaft 3| This shaft is mounted to rotate in suitable bearings 32, 32 carried by the side plate 911 and has a worm gear 33 fixed on the other end thereof which is in mesh with a similar gear 34 which is fixed on the outer end of the shaft 35. This shaft is mounted to rotatd in suitable transversely aligned bearings carried by the side plates 9, 9a and has a spur gear 36; fixed thereon which is in mesh with the rack 31 into which the adjacent margin of the track I is formed. The friction wheel 28 is located within the overhanging rim 38 of the pulley I2. The belt 39 or other flexible member, whose tension it is desired to regulate, operates about the, pulley I2 as shown in Figure 1. As said flexible member acquires slack the springs 20, 2| will cause the pulley 9 to move so as to bring the rim 38 into frictional contact with the friction wheel 28 which will be thereby rotated. The shaft 3| will be correspondingly rotated and the gear 34 5 and shaft 35 turned to effect the movement of the entire tensioning device along the track l to 'take up the slack of the flexible driving member until the resistance of said driving member on the pulley I 2 is suflicient to release the rim 38 from said friction wheel 28.

If the flexible driving member, or belt, 39 is operating under the required tension and if a sudden change of temperature, or a similar cause, should increase the tension, then the pulley I2 is moved toward the friction wheel 28 until its enlarged hub 40 comes into frictional contact with the friction wheel 28 which will cause the shaft 3| to be rotated in the opposite direction to effect the movement of the entire tensioning de- 2 vice along the track so as to relieve the tension on the driving member and rotation in said direction will be continued until the hub 40 has moved out of frictional contact with the friction wheel 28.

The rod 23 may be adjusted so as to give the springs 20, 2| the required tension to normally maintain the pulley l2 in such position that the rim 38 and hub 40 will be clear of the friction wheel 28 but in readiness to come into frictional 30 contact therewith should the driving member acquire too much or too little tension so as to efficiently control said tension and maintain it within the required range; and the spring 25 may be also adjusted by suitably adjusting the nut 26,

for a similar purpose.

As hereinabove indicated, in adjusting the springs 20, 2| or the spring 25 a suitable gauge may be connected to the lug ll for the purpose of gauging, and thus determining, the amount of such adjustment. As hereinbefore indicated the device herein disclosedis applicable to various types of machinery to which power is transmitted by belts, cables or the like. It is of simple construction, may be cheaply and easily produced and maintained at a minimum of expense and when installed is at all times in readiness to properly regulate the tension of the driving member so as to take up the slack or relax excessive tension as the case may be in an efficient and automatic manner.

What I claim is 1. A tension regulating device comprising a casing, a track on which the casing is mounted to move, a pulley adjustably mounted on the casing, a friction wheel rotatable on the casing, means including a. flexible driving member operating around the pulley and a yieldable member connected to the pulley and casing effective to frictionally connect the pulley and friction Wheel in accordance with variations in the tension of said driving member and means driven by the friction wheel and operatively connected with the track for moving the casing on the track in accordance with the direction of rotation of the friction wheel.

2. A tension regulating device comprising a rotatable idler pulley for a flexible driving member, a support on which the pulley is mounted, a track on which the support is mounted to move, a yieldable member on the support and connected to the pulley, said pulley being movable in one direction, on the support, in response to tension on the driving member and in another direction in response to said yieldable member, annular friction surfaces on the pulley, a friction wheel on the support between said surfaces adapted to be rotated by said surfaces when the latter are moved into contact therewith and operative connections on the support between the friction wheel and track whereby the device is adjusted in accordance with the direction of rotation of the friction wheel.

3. An idler comprising a frame, a sheave having annular friction surfaces and movably mounted on said frame and formed to carry a belt, yieldable means formed to resist the movement of the sheave due tobelt tension, means for regulating the. tension on said yieldable means, means for movably mounting said frame on a stationary support, a friction disc formed to contact said sheave and rotatably mounted in said frame, means associated with said disc, frame and mounting means whereby rotation of said disc moves the frame relative to the mounting means.

4. An idler comprising a frame, a sheave movably mounted in said frame and formed to carry a belt, said sheave being movable into two extreme positions, yieldable means formed to resist the movement of the sheave due to belt tension, means for movably mounting said frame on a stationary support, a friction disc on the frame formed to contact said sheave in the extreme positions and rotate therewith, alternately in opposite directions, means associated with the disc, frame, and mounting means whereby rotation of the disc will be effective to move the frame relative to the mounting means, thereby varying said belt tension and allowing the sheave to return to a position intermediate the extreme positions.

JAMES A. WEBB. 

